A way to mount through `CI_BUILD_DIR` when using podman (pipglr) [dind]

I am using Qontainers / Podman In Podman GitLab Runner · GitLab which lets me run gitlab-runner together with podman as a Gitlab runner instance (lets call it GR_I). It uses a container volume pipglr-cache (mounted at /cache) which is attached to GR_I and which holds the checkouts for the CI runs.

With the following config:

check_interval = 0
   concurrent = 4
   shutdown_timeout = 0

   [[runners]]
     executor = 'docker'
     id = 32854861
     name = 'pipglr'
     shell = 'bash'
     url = 'https://gitlab.com/'
     [runners.docker]
       cache_dir = '/cache'
       disable_cache = false
       disable_entrypoint_overwrite = false
       host = 'unix:///home/runner/podman.sock'
       image = 'registry.fedoraproject.org/fedora-minimal:latest'
       network_mode = 'host'
       network_mtu = 0
       oom_kill_disable = false
       privileged = true
       pull_policy = ['always', 'if-not-present']
       shm_size = 0
       tls_verify = false
       volumes = ['/cache', '/home/runner/podman.sock:/var/run/docker.sock:rw']

Note: I am mounting through the podman socket, to reuse it in my job containers

I can do stuff like:

podman-remote-alpine:
  stage: format
  image: alpine:latest
  variables:
    CONTAINER_HOST: unix://var/run/docker.sock
  script:
    - apk add podman
    - podman info
    - podman run alpine:latest cat /etc/os-release

but I am unable to mount CI_BUILD_DIR through to a podman run command.

podman-remote-alpine:
  image: alpine:latest
  variables:
    CONTAINER_HOST: unix://var/run/docker.sock
  script:
    - apk add podman
    - podman run -v "$CI_BUILD_DIR:/data" alpine:latest ls /data

This is due to the fact that the path $CI_BUILD_DIR (aka /build) is interpreted as a path on the GR_I (the container which runs the gitlab-runner and podman) and that does not exist.

I wanted to know if its somehow possible to know this path on the HOST (aka something like /cache/runner-9trd64rgf-project-51433680-concurrent-0/c33bcaa1fd2c77edfc3893b41966cea8). If it would I could correctly mount the above build directory.

Is this requirement to run podman run -v "$CI_ BUILD_DIR:/data" somehow possible with the above setup?

Maybe a podman-remote service which runs next to the alpine:latest (does not work as I cannot start services: with podman on GR_I…)